Frankie (Frankie Avalon) and the gang are hitting the beach for some good old-fashioned shenanigans. To get the party underway, the manager (Paul Lynde) of pop singer Sugar Kane (Linda Evans) decides a skydiving publicity stunt will really do the trick. As Frankie and the others are pulled into the plan, things get out of control.

Throw in Bonehead (Jody McCrea) falling in love with a mermaid (Marta Kristen) and a kidnapping biker (Harvey Lembeck), and the party's just getting started.